How Hand Sanitizer Works (And Why It Isn't a Substitute for Soap)

iStock
iStock

You likely know it's mostly alcohol. So why doesn't hand sanitizer look, smell, and feel like the stuff doctors use to clean their tools? (Or for that matter, the kind we drink?) The difference is in the details, as the American Chemical Society's Reactions video explains below.

Technically, most popular hand sanitizers are made from forms of alcohol including ethanol (the same stuff in wine, beer, and liquor) and isopropanol, which is found in rubbing alcohol. These dissolve the outer coating of viruses and bacteria, which ultimately ends up killing the pesky skin hitchhikers.

That said, the substances above only comprise around 70 percent of the active ingredients in hand sanitizer. The rest are added to give the drugstore staple its gel-like consistency, softening properties, and its botanical fragrance. In some cases, manufacturers might even add some foul-tasting compounds to the mix, to deter users from potentially taking an ill-advised sip.

These mixtures are typically billed as "killing 99.99 percent of germs." In lab conditions, they can nearly eradicate certain strains of bacteria, but not all of those commonly found on your hands. Nevertheless, they do a pretty effective job.

Some health-conscious purchasers may worry that hand sanitizer will lead to the emergence of super-germs, kind of like antibiotic resistance. Here's the good news: Bacteria can't develop ultra-strong proteins or membranes as a response to being detonated by alcohol, so feel free to keep on squirting the aloe-scented stuff all winter long. The bad news? It doesn't physically wash dirt from hands. For that, you'll have to rely on old-fashioned soap and water (which don't fit nearly as conveniently into pockets or purses).

Find out what other compounds lurk invisibly inside your trusty bottle of hand sanitizer, and how it works to blast germs, by watching the video below.

Celebrate the Holidays With the 2020 Harry Potter Funko Pop Advent Calendar

Funko
Funko

Though the main book series and movie franchise are long over, the Wizarding World of Harry Potter remains in the spotlight as one of the most popular properties in pop-culture. The folks at Funko definitely know this, and every year the company releases a new Advent calendar based on the popular series so fans can count down to the holidays with their favorite characters.

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Right now, you can pre-order the 2020 edition of Funko's popular Harry Potter Advent calendar, and if you do it through Amazon, you'll even get it on sale for 33 percent off, bringing the price down from $60 to just $40.

Funko Pop!/Amazon

Over the course of the holiday season, the Advent calendar allows you to count down the days until Christmas, starting on December 1, by opening one of the tiny, numbered doors on the appropriate day. Each door is filled with a surprise Pocket Pop! figurine—but outside of the trio of Harry, Hermione, and Ron, the company isn't revealing who you'll be getting just yet.

Calendars will start shipping on October 15, but if you want a head start, go to Amazon to pre-order yours at a discount.

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Why Can’t You Smell Your Own Breath? There Are a Few Theories

Hands are built-in tools for detecting bad breath.
Hands are built-in tools for detecting bad breath.
SIphotography/iStock via Getty Images

The fact that we rarely catch a whiff of our own breath seems fishy. For one, our noses are only a philtrum’s length away from our mouths. We also don’t have any trouble inhaling other people’s stale carbon dioxide, even with a solid few feet between us.

Though we don’t yet have a decisive scientific explanation for this olfactory phenomenon, there’s no shortage of promising theories. According to BreathMD, it could be that we became so accustomed to smelling our own breath that we simply don’t notice its odor anymore—similar to the way we can’t detect our own "house smell." This kind of habituation doesn’t just inure us to unpleasant aromas, it also leaves our noses free to focus on unfamiliar odors in our environment that could alert us to danger.

As HowStuffWorks reports, another hypothesis suggests that we’re more conscious of other people’s halitosis because breath released when speaking is different than breath released when exhaling regularly. All the tongue movement that happens when someone talks could push odors from the back of their mouth out into the air.

But if that’s true, it seems like you’d be able to smell your own breath—at least when you’re the one doing the talking. Which brings us to the next and final theory: That your bad breath dissipates before you get a chance to inhale it. When someone else exhales, you’re inhaling their air almost simultaneously. When you exhale, on the other hand, you have to wait until you’ve reached the very end of your expiration before breathing back in again. By that time, the malodorous particles may have already dispersed.

Even if you’re blissfully unaware of how your own breath smells, it could be a little nose-wrinkling for others—here are some tips for getting rid of halitosis.